Performance evaluation of several sequencing batch biofilm reactors with movable bed in treatment of linear alkyl benzene sulfonate in urban wastewater

Detergents are one of the major environmental pollutants whose consumption will increase by increasing the level of health of countries, which can cause many problems if they are not unfiltered and exposed to the environment. After soap, linear benzene sulfonate is the most common household detergent and it is used in more than 100 countries around the world as a raw material for the production of surfactants such as washing powders, dishwashing liquids and other detergents. Among the various methods of treatment, biological processes are the most promising ones. The aim of this study is to evaluate the performance of a moving bed sequencing continuous-inflow reactor (MSCR) for linear alkyl benzene sulfonate (LAS) removal from municipal wastewater at different operating conditions. In this research study, a Plexiglass pilot with dimensions of 54 × 25 × 25 cm, and total volume of about 35 L and used volume of 30 L was used. The reactor contained 70% of K3 (Kaldnes) media, and the remaining 30% was considered as the functional volume. Results showed that the MSCR has a high capability in the treatment of municipal wastewater polluted by LAS and a good flexibility to input variation of both LAS and organic load. The maximum removal efficiency obtained at hydraulic retention time of 2.5 h, with input organic load of 300 mg/L and input LAS of 15 mg/L, was 96.4%. The maximum efficiencies obtained at hydraulic retention time of 2.5 h, with input organic load of 500 mg/L and input LAS of 15 mg/L and 25 mg/L, were 88.7%, and 92.2%, respectively.